What will be the best renewable source of energy in 2050?

Jul 31 2012:
I am a Mechanical Engineer. First, scientists don't really have much to do with applied technology; they may do a lot of relevant research, but the nuts and bolts (which add up to dollars and cents) are determined by engineering, production, distribution, etc. You asked about what will be the 'best' renewable energy source. How 'best?' e.g. most portable, least impact, least capitol expenditure, least cost in a major system (city size), least cost in a house sized system, geographic location, etc, etc. And of course, if you did specify more or less precisely an application we could analyze, a) there would still probably be choices with subjective differences, b) the answer will change over time. In the current issues of Mechanical Engineering, this issue is being discussed, and the consensus is that there are no clear winners; there are too many unknowns to be worked out in the various alternatives.
You specifically asked about renewable resources, which precludes nuclear fission, fusion and fossil fuels. Sadly, by 2050 we will probably still be using these. Geothermal is pretty picky about siting, so not scalable up very far. I live in Washington State and I saw a study done not too many years ago on Vashon island in Puget Sound, looking at all the extant alternatives for supplying renewable energy there. By a pretty wide margin, solar was the only one that even had a chance of supplying significantly all the need (not. Vashon is a semi-rural place, above 45 degrees latitude. I'm not saying solar cells is 'the' answer because even within the solar field, there is a ton of diversity; hot water can be collected with just pipes and a pump. Electricity can be generated by solar cells, stirling generators, steam towers, salt ponds, etc. etc.
Frankly, from my perspective, the most urgent need right now is to stop constructing buildings using old technology that consumes energy like it is going out of style. We can pretty much make a zero-consumption house now

Aug 6 2012:
For the bulk of our energy resources, a 44 year old idea, power satellites, might become the dominate power source.

It can scale to tens of TW, the energy payback time is less then 2 months.

The reason it has not been taken seriously is the high cost of lifting parts to GEO. Rocket performance is limited by the energy in chemical fuels, barely enough to get 2% of takeoff mass to GEO.

If you can sidestep the limitation of chemical fuels, then the payload fraction goes way up. Solid state lasers, grown up versions of the tiny ones in CD players, will do that. I.e., unrelated developments in electronics are about to cause a "Black Swan" effect on space transportation.

Burning hydrogen in air is even better than lasers—till you run out of air. The current concept is an air breathing rocket plane such as Reaction Engines' Skylon for the first 2 km/s velocity gain and hydrogen heated to 2700 deg K by a multi GW laser in GEO for the rest of the velocity to LEO. That gets about 25% of the starting mass on the runway to LEO as payload. From there up, lasers deliver around two thirds of the mass in LEO to GEO, about 18 tons out of 120 or 15%. Three times an hour.

That gets the cost down to under $100/kg, the cost of power plants to $1.6 B per GW, the cost of power to 2 cents per kWh or less and the cost of synthetic gasoline made with electric power to a dollar a gallon.

Further bootstrapping (10% of new power sat construction) allows lift capacity to grow by a factor of 3 every year (based on laser capacity). Goal is energy at such low cost that humanity can painlessly get off fossil fuels in two decades. Cost is about 1/3 of the $500 B for a Mars mission *and* you get a Mars mission virtually for free by sending the 100th power sat (all 25,000 tons of if) to Mars for local propulsion. (The high cost is due to having to haul up the first power sat with conventional rockets.)

Jul 29 2012:
I think it will (have to) be a simple system at the level of each household. Simple meaning mechanical rather than nuclear or chemical, because of the risk values. At the household level because we have to overcome the transport variables (miles of wire, transformers, whatever). As a hypothetical example, imagine something like a roulette wheel where the rim and the ring around it are magnetic opposites. With such a low-friction coefficient, a small input can sustain output creating an amplification. I don't know if this works, but look at how low the risk/repair costs for something like that would be.

Jul 29 2012:
We are on the same page Erik ( see my post to Debra Smith above). I realy feel that all renewable energy will be co-opted and monopolized by the plutonomy if we do not have a household controled site specif, lo tech lo cost solution available.

As I am sure you have noticed, public policy onn renewable energy globally is being driven by the plutonomy ad certainnly not in the direction of household specific generation using lo tech equipment.

That leave sit up to us, "we the people" of the world to find and make these household specific lo cost lo tech choices..if there is no one to but what he plutonomy is offering..and if we stay on our pols to include and provide strong incentives for household ( and community) specific energy generation independent of the grid.

If on a per household basis in Maine the subsidy and electricity costs increases being given to wind power and thr grid to collect and distribute windpower were divied up every single person ad every single business in Maine could be off the grid and on endlessly renewable low cost lo tech energy.

Household specific lo tech renewable energy will not get the subsidies and tax credits unless "we the people of the globe" demand that and make that choice for ourselves ahead of public policy.

Aug 5 2012:
We will properly revisit some of the older ones.
Solar Chimney Spain 1980's did not work. 200 m diameter 200 m tall.
Simple revisit on basic arrangment with a little attention to proper science choices in that arrangement rather than leaving things to chance by lack of attention in arrangement. Factors of 100's are available to imrove things when you look at why it did not work.
Difficulty is attracting funding for simple revisit on small scale as proof of concept before rushing into bigger plants or destroying credibility of the option based on one failed but very expensive test.
1980's 50 million odd Euros. Failed.
Simple 15.5 m dia x 14 m tall model with simple but rather effective on paper changes needs only 166,000 USD over 2 years to properly document, trial feasibility build at 15.5m dia by 14m, and determine how to scale it up to large.
Any venture capitalist takers?

I will state my position again. The web shows the same fundamental mistakes as Spain. Spain produced 0.1% efficiency according to unbiased academic reports. Without changes it will not succeed. No fundamental changes shown.

Environmission 2000 public quotes on costs for 1000 m tower in Australia well under typical construction costs that is why from 2000 on its public cost estimates escalated but still not enough. You can track their predictions in published documents 2000 to 2009. That is why scheme now gets scaled back 200MW to 50MW. Still not a project.

China is same arrangement. You cannot scale up a 0.1% plant design to larger and expect improvement no matter how well meaning the intent of renewables. Rethink is required and it is possible. Simple fundamental errors exist in the arrangement.

I will again state to get funding is difficult for a basic revisit, but revisit is necessary.

Electrical transmission was dead in the water a long time ago despite its promise until an individual approached and stated he knew what was wrong and could make it work as it was so simple. Took a long time till someone took him seriously and he drew the coils of the first transrformer on a single piece of paper. Hola. The rest as they say is history.

Don't want to distract from overall conversation so will leave it at this.

Aug 6 2012:
Try taking advantage of vortices.
You could borrow the tubercle design concept from Whalepower to redesign the leading-edge finish of your sails. This has been proven to decrease the minimum windspeed needed to begin operation and to improve output power by 20% during field testing.
(basically it uses a serrated edge)

Additionally, you could affect the local air environment:
I would suggest trialling designs to fit to the support structure in order to funnel air into the effective sail region by decreasing air pressure at your rotational centre. This could yield very large improvements in output power.

Aug 5 2012:
I worked at a wind energy company. During my stay mt beleif that wind energy is the best solution was challenged. Granted - it is far better than oil. But its still far from perfect!

-The oil in every windmill has to be changed often. (we are talking a lot of oil here)
-The current buisnessmodel is sending a sparepart to several underdevisions of a company, hereby increasing the price of the item. This leads to a lot of co2 emission because of the excessive transport.
- The machine emits a low-frequence constant noise which is feared to affect humans and animals in a negative way.

Dont understand me wrong: i am a fan of windmills. I'm just saying that we need to get better at building them.

Regarding the "best" renewable solution, I think we need a healthy mix of them all. I especially would like to see big development in sea-wave energy. Sadly it seems that it will be one of the only things we can use the oceans for anyways, as we are in the process of destroying most life in it.

Aug 8 2012:
David has every right to show what he currently believes will be the best source. Since you, Debra, seem to already have submitted your opinion, I suggest you allow him to expres his ideas, even if they are biased. Thank you very much.

Aug 6 2012:
Thanks for your comment and your spot on questions.
In fact, right now, I am the organization.
Read A Humble Introduction on the site if you are interested further.
I hope it would give you an honest idea of my intentions.
This is very new territory for me. I need to make a living, but the idea must go beyond
making anybody rich, including myself. I am in the 99%, just getting by. I have a patent pending, big deal. I can't pay my medical bills.
I want to see this wind turbine design do some good for people. I am struggling
over just how to share / sell / give away what I have managed to develop so far so, yes I can make some money, but that it doesn't fall into 1% profiteering hands.
I am working on open source materials, which is a lot of work.
Thanks in advance for any other thoughts you may have.
all good things,
DB

Aug 6 2012:
After being on this site for some time, and with an MBA in marketing, I simply believe that this is not the place for business self promotion especially when persons think this is a targeted market who thinks as they do and when they paste in their contacts on several of our threads. Then, I think that sense of inappropriateness can be fairly expressed.I am personally pro-wind as Lenart has learned and while I appreciate learning I do not appreciate it being held out like a carot. If you wish to contribute to the mass of knowlege you are of course more than welcome but if your motivation is to profit from the like minded this is NOT the place. TED has paid advertisers that make this format possible.

Jul 31 2012:
The "best" source will be the one that provides the most electricity at the lowest cost when ALL of the costs are included in the calculation. Now, this calculation includes only the direct costs of production, and environmental costs are ignored. Unless we do something to change this calculation, the most widely used source will be the one that is cheapest and the "best" will be used by a few hardcore environmentalists. IMO, changing this calculation is the major challenge in the quest for a sustainable economy. This is a matter of values, and that will be extremely controversial. Environmentalists are already fighting some renewable energy projects because of the environmental effects, and somebody should.

Jul 28 2012:
Electro magnetic spectrum has more possibilities if we learn to try and control it. Take the super conductor that levitates, due to the manipulation of magnetic waves. imagine if we could some how make a plain that could some how ride the waves like on a track. Who know there might be something in this idea.

Jul 29 2012:
This is being explored by scientist around the world and interestingly sound ( sonar luminescennce) is also a possible source of cold fusion..a long way to go in knowing how to produce it in controllable ways. perhaps something we humans knew and had once and just forgot.

Jul 30 2012:
Thanks Enrico..both interesting links..hadn't heard of the challenges to the sonar luminescence experiments or of Sandia's Z-Machine.

Cold Fusion is definitely a long term holy grail of cheap infinitely renewable energy..perhaps something promisng will happen before 2050 even if that technology may not be widely available by then.

What appeals to me about it is the possibilty that it could be household/community/business specific..available without needing a grid or distribution system and called on demand in direct response to demand..at least that's my dream/ vision.

Sound/vibration ( a wave energy) may have powers we have forgotten or don't yet understand..along with so much of what we don't know understand. Is it Nasa that is doing the experiments with acoustical levitation? So far only a tiny ball..but who knows what answers the real workings of the universe offer us that are yet undiscovered or even imagined?.

Jul 30 2012:
Superconductor research is increasingly interesting. Many people are wanting to exploit graphene (scientifically in-fashion), I am sure there are applications for either that are difficult for a single person to concieve...

I have always enjoyed the idea of lightning harvesting, regardless:
Solar should satisfy domestic requirements while using the grid as backup
Commercial and industrial requirements will always need large power plants (including geothermal, hydro, and windfarms)

I expect to see tritium as an abundant commodity, sometime well after the first commercial fusion station is built, which would be very optimistic to say before 2050.

I would be thoroughly pleased to see LFTR's available in every Country, producing useful power and byproducts including breeding tritium for fusion.

Serious improvements in transport efficiency will come from step-change technologies. Industrial research into step-change technology is increasingly more neccessary for sufficient competetive edge.

Jul 28 2012:
Pat caught my attention with soylent green. What we do will be limited by physical laws. I am reminded of a Feyman comment on PBS to that type question. I found a recent plasma physics lecture on Ted recently very interesting and very disconcerting. Radioactive materials contained by a magnetic bottle. I hope, but.... We have seven (7) billion people and growqing in a world with real physical limits. We have long been warned of limits by scientist and populizer's Asimov, Meade, etc. etc. but Bubba doesn't listen.

Jul 27 2012:
I'd say solar in some form. After all, most energy have their origin in solar. Perhaps if we can use photosynthesis in some clever way. For nuclear, molten salt reactors is promising as a safer alternative. I'm sceptical if we can make cold fusion work before 2050. And hot fusion is coupled with extensive risks.

Aug 10 2012:
I would suggest water. As we are 80 percent water we will always hopefully be very careful about not contaminating it or the natural filters and condensers the planet uses to maintain a fresh water supply. I mean looking after the trees and forests and I mean making sure global warming does not melt too much of the polar ice caps. The weather pattens have been very odd in Europe this year because the air currents and sea currents are in the wrong place. By air current I mean jet stream and by sea current I mean North Atlantic Drift. Everyone is going down with head colds (I know this is a virus) and hayfever. People are developing really nasty respiratory infections. Everyone having to go to work isn't helping because people sneezing on the buses is spreading the viruses by droplet. Mother Nature has her filters and the most effective treatments are plant based. So I say water. I don't necessarily mean hydro-electric and it would be better if it was salinated water. I think there is something in the ionisation of water that might be worrth exploring.

Aug 9 2012:
The first thing to do is to take a long, hard look at energy usage, and to make that as energy-efficient as possible. It is unbelievable how much we squander our energy (and natural resources) because it is still relatively cheap.

Only when USAGE becomes efficient, will we then have a chance of powering our lifestyles with renewables by 2050.

Wherever there is a problem such as this, take a look at how nature solves it. As one example, biomimicry can solve problems such as natural air-conditioning by designing buildings that mimic termite mounds. This principle is already being used successfully in Zimbabwe:

Aug 7 2012:
Thank you so much for two marvelous insights! I just recently saw the Whalepower design, but it didn’t dawn on me that vortices could have a dramatic positive on our design as well. But, of course! Wow, thanks! I will be getting in touch with them.

And yes, I think there are a number of ways to funnel air flow using the support structure or other architectural features depending on where the turbine is being used. I know from living in New York City years ago that there are places in the urban environment that are like wind tunnels! People far brighter than I can certainly determine the best locations for potential urban wind turbines, and if a location could be greatly improved with the addition of some form of wind funneling structures, that in itself could lead to some very exciting, creative as well as functional, design challenges.

Also, I will share with you the irony, that upon receiving your two terrific ideas on how this idea could be improved, I also received notice from the TED Conversations Admin that the conversation I had hoped to start by posting our website was removed as it is “too self-promotional for the TED.com community”. I am a TED community virgin, and regret any over reach on my part. In fact, I am struggling, having been inspired by over 120 TED speakers, on how to go about sharing this idea/invention so that it is put to the best use as quickly as possible by as many people that could benefit from it as possible, (open source, collaboration, etc.), and yet protect it so it doesn’t go down some get-rich-quick route for the already rich, or wallow in some bureaucratic research lab for years sucking up grant money and getting nowhere. I thought what better place to go for ideas, but TED! Now I know. But, any thoughts you have on that dilemma would be appreciated as well. I would certainly like to continue our conversation in the proper forum, perhaps by email, as we are a bit off topic for this thread.

Aug 2 2012:
I suspect that after our diet of renewables by 2050, we'll be on the way to create new core sources using both fission and fusion safely, i.e. nuclear waste destruction, secure protection of nuclear fuel and accident containment of production sites.

We might even come up with new sub-nuclear sources of energy that don't involve the release of energy when the cores of atoms are split or united.

Aug 1 2012:
Have a look at Bloom Energy. this works with hydrocarbons (at the moment AFAIK) but if it could work with biogas a full system could be installed with each house. Bio degradable material can generate the gas which these fuel cells can convert directly to electricity. Plus you don't have any transmission losses.

Jul 30 2012:
Solar energy, undobutlessly. Powerful, cheap, clean, sustainable,.... and multipurpose also (wait and you'll see!) And don't forget dark energy. It may be a grateful and amazin surprise. I'd like living enough for watching it.

Realistically, for even the most optimistically speculative fusion technology we are looking at 2050.
We could have a LFTR built and operating by 2030, which arguably could breed tritium for supply to a ZN or Tokamak reactor. Aneutronic fusion would require a tritium breeder like the LFTR...
"

Jul 29 2012:
The google guys were betting on geothermal, i read somehwere and maybe it is just wishful thinking on my part or gratitude for having all my questions answered but I think those guys usually know something.

Jul 29 2012:
Geo thermal has become much talked abut here in Maine because of the presence of a group specilaizing in that. ( I think it is called GO Logic) They built a demo 3 bedroom home two years ago for a very modest price ( $350k???) which heats for $350 per year..that is from supplementary electric baseboard heat which is needed only in extreme cold .

I did some research contemplating my next and hopefully last home..there are issues which somehow need to be overcome. Key parts of the very deep underground system need redoing after 15 or 20 years..and the process of installing geothermal may not be suitably for fragile natural settings .

I love that it is building specific and generated from the earth on the property from natural and simple processes that require very little in the way of a technical assist... That protects it from the threat of monopoly and profiteering that is happening now with industrial wid globally and here in Maine.

Jul 29 2012:
I read about the positrons and anti matter and the equal amount of energy they generate compared to a nuclear reactor without any hazards , so I feel that should be the future sources of renewable energy

Jul 30 2012:
Could you elaborate on this? I am not familiar with any way of using positrons and anti-matter to generate useful energy. The positrons and anti-matter would have to be "harvested" so to speak, not generated by humans, in order to be useful for energy production. What are your sources on this matter?

Jul 29 2012:
Think it will be mix of energy efficient smart systems and mix of solar and wind. also solar cells today are not so efficient. Major work will go in increasing efficiency. The incident energy on earth of solar power is 1kw sq mt. but the efficiency of around 10% means we only can convert it to get between 75w -100w /sq mt after conversion into AC. Most houses around 10 sq mt of surface area so they can generate around 5kw of energy per houshold if we could increase the efficiency to 50%. that means with 8 hours every day you would get 40kwh per day more than enough for most houses.

the other one could be direct conversion from ambient heat to electricty. heat cloaks could make this happen in next 2 decades or so.

Jul 30 2012:
Not really - because the way you would use a smart system is quite different. A few batteries are enough if you use when you match your use with peak generation. For example devices such as washing machines, dryers etc which consume lot of energy will be on standby and will switch on when there is peak energy i.e. during day time. This may not work in all geographies but many countries such systems will make complete sense.

Jul 30 2012:
As you are a UK resident I should enquire how you will heat your home at night, in winter. I live in Australia and still use a heater when the nights are cold. An electric heater uses more energy than any other appliance in your house. If you heat using anything other than electricity you're not really helping the co2 problem. It would work OK in the tropics though.